CVE-2026-110863Better Auth @better-auth/sso before 1.7.3 Authentication Bypass via Personal SSO Providers

Descripción

Better Auth @better-auth/sso from 1.7.0-rc.2 before 1.7.3 contains an authentication bypass vulnerability that allows authenticated users to sign in as other users by registering a personal SSO provider. Attackers can copy a legitimate provider's OIDC issuer or SAML entity ID and assert a victim's subject or NameID, because account lookup ignores providerId, creating sessions for victim accounts.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• GitHub Security Advisory (GHSA-mx9r-x6ww-qjw9) vendor-advisory
• VulnCheck Advisory: Better Auth @better-auth/sso before 1.7.3 Authentication Bypass via Personal SSO Providers third-party-advisory